What do I need to know when buying syringes for my insulin?

The syringe consists of a needle, barrel, and plunger. Syringes come in different sizes. It is important to match the size of the syringe to the dose you’ll take with it. You want a syringe that will hold your entire dose of insulin. For example, if you need to take 45 units of insulin, you would want to use a 50-unit syringe to hold all your dose. A 30-unit syringe (the next smallest size) is handy for giving yourself injections of 30 units or less. Likewise, if you need to inject very small doses of insulin, 1/2 unit for example, use syringes that have 1/2 unit marks to keep doses accurate.

Also, check to see whether you can read the markings on your syringe. A 100-unit syringe holds 100 units of insulin in a volume of 1 cc (or 1 ml). Each line marks 2 units of insulin. A 50-unit syringe holds 50 units of insulin in 0.5 cc of liquid, and each line marks 1 unit. A 30-unit syringe holds 30 units of insulin in 0.3 cc, and each line marks 1 unit. You will need to measure out each dose in units. So, if you can’t see the lines marked on the syringe, you will have problems getting an accurate dose. There are devices you can buy to make it easier to read the markings on the syringe. Your pharmacist or diabetes educator can tell you what supplies are available to help you.

Another good source of information is the American Diabetes Association Consumer Guide published yearly by Diabetes Forecast, the members’ magazine of the American Diabetes Association. The Consumer Guide is also available online at

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.